I'm going with the toomey kit. I want to change my airbox and stock filter as I think it is restrictive. and I think you should re-jet after changing your pipe, at least make sure you are not running too lean. Espeacially considering that Glamis is A: at sea level and B: the sand combined with paddles puts more load on the engine than dirt does.
Just my .02
Oh yea, and ditch the oil injection system, You don't have to buy the 30.00 kit just take the pump off then take out the gearing, then put the pump back on with a solid gasket ( no hole in it ) I just made a gasket with some gasket material,
Then find a plug that will fit over the inlet on the carbureater where the oil line previously connected.
Heres the Toomey web site:
http://www.toomey.com/html/B1.htmHere is a site called Trenga racing which has alot of blaster info.
This link shows how to do the block off kit.... but believe me you can do it for a couple of bucks.
http://www.trengaracing.com/support/OIBOK.shtmlJust remember no matter what you do to it ....it's still a Yamafail